Steam Machine Ultra
The money-no-object build
Asus RoG Maximus VI Impact - £180 / $270
After the chassis this is going to be the other important choice in the build. Valve has opted for Intel CPUs for its prototype and you can pick up some excellent mini-ITX motherboards for its chips.
As we're putting together a seriously high-powered gaming rig it seems churlish not to include the beautiful Asus RoG Maximus VI Impact. It builds on the quality P8Z77-I Deluxe mini-ITX board of the last generation and offers top-end performance in a tiny form factor.
Intel Core i7-4770K - £240 / $330
That RoG motherboard will allow for a healthy chunk of overclocking, especially with a decent cooler attached to it. For that reason I'm going to have to opt for the top Intel Core i7-4770K, as it will deliver up to 4.6GHz while barely breaking a sweat. You wont get that here, with the cooler restrictions of the chassis, but that wont really impact upon your gaming performance at this high level.
The eight threads of the fully HyperThreaded i7 means that, in comparison with the resolutely quad-core i5, you will actually get higher minimum frame rates in-game. You wont find the average frame rate jumping, but with the low end getting a boost games will feel smoother.
Gelid SlimHero - £22 / $34
Gelid's SlimHero is an excellent low profile cooler that is still powerful enough to be able to cope with an overclocked CPU, if only just. It's very slight, but the large 120mm fan will ensure you don't end up with a whiny cooler sitting atop your processor.
Crucial Ballistix Tactical LP DDR3 - £160 / $200
The important thing for a small form factor build is space. When you're working with a powerful, compact cooler like the Gelid, you need to be mindful of the memory you're using. Crucial's Ballistix Tactical LP DDR3 are beautifully designed DIMMs that will sneak under the radar of any overbearing CPU cooler and you can pick up a 16GB kit with a pair of 8GB modules to fill out the dual DIMM slots of the RoG motherboard.
Nvidia GTX Titan - £780 / $1020
What can I say here? If you're talking about the very best then there really is only one graphics card to go for, and hang the expense. Nvidia's GTX Titan is the most powerful single-GPU around (at least until AMD gets all Hawaii on our desktop GPUs) and that's also the top card in the Valve prototype machine so you know it's going to get some SteamOS compatibility lovin' too.
To be honest though it's a total overkill for this rig, and when the GTX 780 (also one of the cards in the prototype) is considerably cheaper with almost identical gaming performance, it really would take a total money-no-object build to consider the Titan a realistic choice.
Samsung 840 EVO SSD, 1TB - £500 / $600
It simply has to be a question of solid state storage for a top-end machine these days. I've been running SSDs in my machines for years and I don't think I could ever go back unless there was no other alternative. In a budget machine, sure, you can get away with an old fashioned disk drive, but for a proper top gaming rig it has to be solid state. And the king at the moment is Samsung, with their speedy, great value 840 EVO offerings. You can pick up a 1TB EVO drive now and that is more than enough to be getting on with.
EVGA Hadron Air - £160 / $190
This is actually the hardest part of the Valve prototype to get a bead on. Currently there are no chassis around that will enable you to do what Valve is creating with their own bespoke case. That's because the enclosure Valve is designing for the prototype is less than 3-inches in height .
They're going to do this by using a 90º riser card for the PCIe slot so they can lay the graphics card on its front rather than having it stand vertically in the case. Nothing I've seen in the market does this right now in the gaming PC space.
So, what to do? Well, there are relatively small alternatives that allow you to use full size graphics card. The latest one is EVGA's Hadron Air and it's my favourite small form factor chassis right now. It even comes with its own installed 500W PSU. My only reservation with the Hadron is that it precludes the use of a closed-loop water cooler installed inside the chassis.
Total price: £2045 / $2644
Yep, that sure is a lot. But these are the choicest components, the priciest and most powerful small form-factor tech in their field. It's the limousine of Steam machines, impressive, but slightly unnecessary. Let's see what we can build on a budget.